Image processing apparatus for converting color to predetermined image

ABSTRACT

An image processing apparatus which converts a color region in an input color image into predetermined images corresponding to colors. The apparatus has a discriminator for discriminating the colors in the input color image, a converter for converting the color regions in the color image into the predetermined images corresponding to the colors discriminated by the discriminator, and a generator for generating the predetermined images and character images representing the colors corresponding to the predetermined images.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image processing apparatus forconverting a color region in an input color image into a predeterminedimage corresponding to the color.

2. Related Background Art

Conventionally, a facsimile apparatus capable of identifying a pluralityof colors from each other, and reading these colors, transmits colorinformation if a receiving facsimile apparatus can record a plurality ofcolors. However, if a receiving facsimile apparatus can only record asingle color (e.g., black) (to be referred to as a monochrome facsimileapparatus hereinafter), the facsimile apparatus transmits binaryinformation reflecting only the lightness of the read color information.

For this reason, when color original information is transmitted to amonochrome facsimile apparatus, the receiving apparatus cannot identifycolors even though the transmitting apparatus faithfully reads a colorimage on a color original.

For example, assume that a color original, on which an upper circulargraph is classified by five colors, i.e., red, blue, green, pink, andyellow, the five colors used in the circular graph are actuallypresented in a lower comment portion, and item names (product names inthis case) corresponding to these colors are added to the colors, asshown in FIG. 8, is transmitted to a monochrome facsimile apparatus. Inthe case of the color original shown in FIG. 8, the receiving apparatusrecords red, blue, and green as black since they have low lightness, andrecords pink and yellow as white since they have high lightness, asshown in, e.g., FIG. 9. Therefore, although a group of red, blue, andgreen, and a group of pink and yellow can be discriminated from eachother, red, blue and green, and pink and yellow in these groups cannotbe distinguished from each other. As a result, information of thecircular graph cannot be correctly recognized.

When the color original shown in FIG. 8 is transmitted to the monochromefacsimile apparatus in a halftone mode, since the same color informationin the circular graph and the comment of the graph is recorded by asingle tone pattern, the correspondence between the circular graph andthe comment portion can be read, and information of the circular graphmay be correctly recognized.

However, when a color original, on which the comment of the graph inFIG. 8 is made by a text, as shown in FIG. 11, is transmitted in thehalftone mode, the receiving apparatus records the information, as shownin FIG. 12. For this reason, even when the comment text includes colornames, the correspondence between the colors and the tone patterns inthe circular graph cannot be determined, and information of the circulargraph cannot be correctly recognized.

The above-mentioned problems occur not only when color information istransmitted to a monochrome facsimile apparatus but also when afacsimile apparatus which can read seven colors, i.e., black, red, blue,green, pink, yellow, and purple transmits information including blue,green, pink, yellow, and purple to a facsimile apparatus which canrecord two colors, i.e., black and white.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an image processingapparatus which can solve the above-mentioned problems.

It is another object of the present invention to provide an imageprocessing apparatus for outputting an image from which a correspondencebetween colors and predetermined images can be easily determined evenwhen color regions in a color image are converted into predeterminedimages corresponding to the colors.

Other objects and features of the present invention will become apparentfrom the following specification and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a facsimile apparatus according to anembodiment of the present invention;

FIG. 2 is a view showing black/white binary patterns corresponding tocolors;

FIG. 3 is a flow chart showing a transmission process for a color image;

FIG. 4 is a flow chart showing the transmission process for a colorimage;

FIG. 5 is a graph showing an image obtained by converting color imagesshown in FIG. 8 into corresponding black/white binary patterns;

FIG. 6 is a graph showing an image obtained by converting color imagesshown in FIG. 11 into corresponding black/white binary patterns;

FIG. 7 is a diagram showing a state wherein a color character "A" isconverted into a corresponding black/white binary pattern;

FIG. 8 is a graph showing an original including color images;

FIG. 9 is a graph showing an image recorded according to a prior arttechnique;

FIG. 10 is a graph showing an image obtained by converting color imagesshown in FIG. 8 into corresponding black/white binary patterns accordingto the prior art technique;

FIG. 11 is a graph showing an original including color images; and

FIG. 12 is a graph showing an image obtained by converting color imagesshown in FIG. 11 into corresponding black/white binary patternsaccording to the prior art technique.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a schematic block diagram showing a facsimile apparatusaccording to an embodiment of the present invention. This facsimileapparatus transmits/receives a still image under the control of acontrol circuit 38.

An NCU (Network Control Unit) 2 makes a connection between a telephoneline 2a and a telephone set 4, a connection between the telephone line2a and a hybrid circuit 6, a holding operation of a loop, and the likeso as to perform data transmission via a telephone switching network.For example, upon reception of a "0"-level signal from the controlcircuit 38 via a signal line 38a, the NCU 2 connects the telephone line2a and a signal line 2b to set the telephone set 4 in a communicationready state; upon reception of a "1"-level signal, the NCU 2 connectsthe telephone line 2a and a signal line 2c to set the facsimileapparatus main body in a communication ready state. Note that thetelephone line 2a is normally connected to the telephone set 4.

The hybrid circuit 6 is a circuit for separating transmission systemsignals and reception system signals.

More specifically, upon reception of a transmission signal via a signalline 28a, the hybrid circuit 6 transmits the transmission signal via thesignal line 2c, the NCU 2, and the telephone line 2a; upon reception ofa reception signal via the telephone line 2a, the NCU 2, and the signalline 2c, the hybrid circuit 6 fetches the reception signal in areception system via a signal line 6a.

A first modulator 8 modulates various transmission control proceduresignals output from the control circuit 38 via a signal line 38b inaccordance with the CCITT recommendation V21 standard, and outputs themodulated signal to an addition circuit 28 via a signal line 8a.

A reading circuit 10 comprises a scanning optical system such as ahalogen lamp, an imaging system such as a CCD color image sensor, or thelike, and can read color image information from an original to betransmitted while color-separating the color image into seven colors,i.e., black, red, blue, green, pink, yellow, and purple. In this case,the reading circuit 10 sequentially reads the color image in units oflines in the main scanning direction on the basis of a control signaloutput from the control circuit 38 via a signal line 38c, and outputsread information to a pattern conversion circuit 12 via a signal line10a.

The pattern conversion circuit 12 detects colors included in each linefrom color image information output in units of lines from the readingcircuit 10. The circuit 12 outputs black image information without anyconversion, converts colors other than black (such colors will bereferred to as "colors" hereinafter) into black/white binary patterns inaccordance with the format shown in FIG. 2, and outputs the convertedpatterns to a first coding circuit 14 via a signal line 12a. The patternconversion circuit 12 also outputs signals of the detected colors to thecontrol circuit 38 via a signal line 12b. In this case, when the circuit12 does not detect colors, i.e., detects only white and black, itoutputs a signal "0"; when the circuit 12 detects red, blue, green,pink, yellow, and purple, it outputs signals "1", "2", "3", "4", "5",and "6", respectively.

The first coding circuit 14 receives image data output from the patternconversion circuit 12 on the basis of a control signal output from thecontrol circuit 38 via the signal line 38c, encodes the received imagedata according to an MR method (Modified Read method; a two-dimensionalcoding method) of K=8, and outputs the encoded image data to a memorycircuit 16 via a signal line 14a.

The memory circuit 16 stores image data encoded by the first codingcircuit 14 on the basis of a write signal output from the controlcircuit 38 via a signal line 38d. The memory circuit 16 reads out thestored image data on the basis of a read-out signal output from thecontrol circuit 38 via the signal line 38d, and outputs the readoutimage data to a first decoding circuit 18 via a signal line 16a.

The first decoding circuit 18 decodes the encoded image data from thememory circuit 16, and outputs the decoded image data to an additioncircuit 22 via a signal line 18a.

A pattern list preparation circuit 20 prepares a list of patterns (FIG.2) corresponding to detected colors and color names on the basis ofdetected color signals output from the control circuit 38 via a signalline 38e. The circuit 20 outputs image information of the list to theaddition circuit 22 via a signal line 20a on the basis of a start signalfor outputting from the control circuit 38 via a signal line 38f.

The addition circuit 22 synthesizes image data from the first decodingcircuit 18 and image information of the list from the pattern listpreparation circuit 20, and outputs synthesized data to a second codingcircuit 24 via a signal line 22a.

The second coding circuit 24 encodes the synthesized data output fromthe addition circuit 22, and outputs the encoded data to a secondmodulator 26 via a signal line 24a. In this case, the second codingcircuit 24 performs coding according to a coding method designated bythe control circuit 38 via a signal line 38g, i.e., an MHC method(Modified Huffman Code method: one-dimensional coding method) or an MRmethod (Modified Read method: two-dimensional coding method). Also, thesecond coding circuit 24 reduces transmission data or performs linedensity conversion in accordance with a recording sheet size of atransmission destination.

The second modulator 26 is a modulator for performing modulation on thebasis of the CCITT recommendation V27ter (differential phase modulation)standard or V29 (orthogonal modulation) standard. The modulator 26modulates the encoded synthesized data from the second coding circuit24, and outputs the modulated data to the addition circuit 28 via asignal line 26a.

The addition circuit 28 adds the modulated synthesized data from thesecond modulator 26 and the transmission control procedure signals fromthe first modulator 8, and outputs the sum data to the hybrid circuit 6via the signal line 28a.

A first demodulator 30 is a demodulator for performing demodulation onthe basis of the CCITT recommendation V21 standard. The demodulator 30demodulates the transmission control procedure signals received via thehybrid circuit 6, and outputs the demodulated signals to the controlcircuit 38 via a signal line 30a.

A second demodulator 32 is a demodulator for demodulating data modulatedbased on the CCITT recommendation V27ter (differential phase modulation)standard or V29 (orthogonal modulation) standard. The demodulator 32demodulates image data received from the hybrid circuit 6 and outputsthe demodulated data to a second decoding circuit 34 via a signal line32a.

The second decoding circuit 34 decodes image data demodulated by thesecond demodulator 32 and encoded by the MHC or MR method in thetransmitting apparatus, and outputs the decoded data to a recordingcircuit 36 via a signal line 34a.

The recording circuit 36 sequentially records the decoded image datafrom the second decoding circuit 34 in units of lines. Note that therecording circuit 36 can be either one of a circuit capable of recordinga single color (e.g., black) or a circuit capable of recording aplurality of colors.

The control circuit 38 provides control for transmitting binary dotpatterns corresponding to colors, which patterns are obtained byconverting color image information of red, blue, green, pink, yellow,and purple, and for transmitting image information of a list of binarypatterns corresponding to colors detected in each page and the detectedcolor names while adding the list to a blank portion of thecorresponding page. Note that the control circuit 38 utilizes aninternal page counter CT and an internal register R upon execution ofsuch control.

A transmission process for color image information by the controlcircuit 38 will be described below with reference to the flow charts ofFIGS. 3 and 4.

The control circuit 38 outputs a "0"-level signal onto the signal line38a to connect the telephone line 2a to the telephone set 4 via line 2b,thereby turning off CML (step S1 in FIG. 3). It is then determinedwhether or not a transmission mode is set by a predetermined switch (notshown) (step S2). If NO in step S2, the control circuit 38 executes aprocess corresponding to another mode (step S3), and the flow returns tostep S1.

On the other hand, if YES in step S2, the control circuit 38 sets aninitial value of "1" in the page counter CT (step S4). The controlcircuit 38 controls the signal output on the signal lines 38c and 38d tostore image data for one line read by the reading circuit 10 in thememory circuit 16 (step S5). In this case, of the image data stored inthe memory circuit 16, images corresponding to colors are converted intoblack/white binary patterns by the pattern conversion circuit 12. Thecontrol circuit 38 receives detected color signals from the patternconversion circuit 12.

The control circuit 38 then stores the input color signals in itsregister R in correspondence with the page No. in its page counter CT(step S6). In this case, if the same color signal as a signal to bestored has already been stored, the control circuit 38 does notrepetitively store the signal.

A determination is made whether or not reading for one page is finished(step S7). If NO in step S7, the flow returns to step S5; otherwise, itis checked if there is a next original (step S8). If YES in step S8, thepage No. in the page counter CT is incremented by one (step S9), and theflow returns to step S5.

However, if NO in step S8, the control circuit 38 outputs a "1"-levelsignal onto the signal line 38a to connect the telephone line 2a to thefacsimile via line 2c, thereby turning on CML (step S10). The controlcircuit 38 then calls a designated transmission destination (step S11).A determination is made as to whether or not colors are stored in theregister R (step S12).

If NO in step S12, this means that all pages of image data stored in thememory circuit 16, which is to be transmitted, consist of black/whiteimage data alone, normal transmission is performed. More specifically,ante-procedure signals are transmitted and received (step S13), normalbinary image data is transmitted (step S14), and post-procedure signalsare transmitted and received (step S15). Then, the flow returns to stepS1. In the normal transmission process, the control circuit 38 does notperform output start control for the pattern list preparation circuit20, as a matter of course.

On the other hand, if colors are stored in the register R, this meansthat image data to be transmitted, which image data is stored in thememory circuit 16, includes color image data. In this case, the controlcircuit 38 sets an initial value "1" in the page counter CT (step S16 inFIG. 4). Then, the color signals in the register R corresponding to thepage No. in the page counter CT are output to the pattern listpreparation circuit 20 via the signal line 38e (step S17). Thus, thepattern list preparation circuit 20 prepares image information and thecolor names of a list of patterns corresponding to colors converted andused in the page indicated by the page counter CT.

The control circuit 38 transmits and receives ante-procedure signals viathe signal lines 38b and 30a (step S18). The control circuit 38 readsout image data for a page indicated by the page counter CT, andtransmits the read out image data (step S19). In step S19, the controlcircuit 38 outputs a start signal for outputting to the pattern listpreparation circuit 20 via the signal line 38f, so that the listinformation of patterns corresponding to colors and the color names isinput to the addition circuit 22 in synchronism with input of image dataof a blank portion from the first decoding circuit 18 to the additioncircuit 22. Thus, the addition circuit 22 adds the list of black/whitebinary pattern used in a page indicated by the page counter CT, and thecorresponding color names to the blank portion of the page. Also, thecontrol circuit 38 instructs a coding method to the second codingcircuit 24 via the signal line 38g, and also instructs reduction or linedensity conversion corresponding to the size of a recording sheet in atransmission destination to the second coding circuit 24 via the signalline 38g.

With this transmission process, two pieces of color image informationshown in FIGS. 8 and 11 are respectively recorded as black/white binarypatterns by a receiving apparatus, as shown in FIGS. 5 and 6. Note thatthe two pieces of color image information shown in FIGS. 8 and 11 areso-called solid-printed color images. For example, color informationrepresenting a character "A" printed in red is similarly recorded as ablack/white binary pattern, as shown in FIG. 7.

Upon completion of the process in step S19, a determination is made asto whether or not transmission of image data for one page is finished(step S20). If NO in step S20, the flow returns to step S19. On theother hand, if YES in step S20, the page No. in the page counter CT isincremented by one (step S21), and a determination is made as to whetheror not transmission of all pages of image data in the memory circuit 16is finished (step S22). If NO in step S22, the flow returns to step S17to repeat the same process as described above. On the other hand, if YESin step S22, the control circuit 38 transmits and receivespost-procedure signals via the signal lines 38b and 30a (step S24), andthe flow then returns to step S1.

In this embodiment, six colors, i.e., red, blue, green, pink, yellow,and purple are used as colors, and these pieces of color imageinformation are converted into predetermined binary pattern informationcorresponding to the colors, and the binary information is transmitted.However, the colors to be converted into binary information of patternsare not limited to the above-mentioned six colors.

When colors which can be read by a transmitting apparatus include acolor which can be recorded by a receiving apparatus, color informationof the color itself may be encoded and transmitted. In this case, it ishard to check a coincidence between readable colors of a transmittingapparatus and recordable colors of a receiving apparatus, and to setcolors to be transmitted as color information and colors to betransmitted as converted binary pattern information in eachtransmission. Thus, recordable colors of the recording apparatus areregistered in advance in correspondence with address information such asa FAX number, and colors to be transmitted as color information andcolors to be transmitted as converted binary pattern information can beautomatically discriminated on the basis of the registration content,thus improving a user's convenience.

When the list of patterns corresponding to colors and the color names isadded to a blank area of a recording sheet, the size of the listinformation may be determined in accordance with the size of the blankarea.

In the above embodiment, the reduction or line density conversionprocess of transmission data according to the recording sheet size of atransmission destination is performed by the second coding circuit 24,however it may also be performed by the first decoding circuit 18.

If it is determined that original image information to be transmittedincludes the same or similar pattern as or to that used for conversion,the pattern can be inhibited from being used in conversion. In thiscase, a pattern of another color which is not the same as or similar tothe pattern included in original image information and is not used inconversion can be alternately used (in this case, the correspondingcolor name is also changed, as a matter of course). In order to avoidthe appearance of the same or a similar pattern as much as possible, aplurality of patterns may be assigned to each color, and a pattern whichis not the same as or similar to the pattern included in original imageinformation may be selected and used.

In the above embodiment, the list of patterns used in a page and thecorresponding color names is added in units of pages. Alternatively, thelist of patterns used within a range of all pages to be transmitted, andthe corresponding color names may be collectively added to a blankportion of a predetermined page (e.g., the final page).

Also, the list of patterns used within a range of all pages to betransmitted, and the corresponding color names may be transmitted as anew page separate from pages of original information to be transmitted.

The reading circuit 10 may read original information whilecolor-separating it into three color components, i.e., red, green, andblue, and the colors of images on an original may be determined on thebasis of these three color components.

The present invention can also be applied to a duplicator or a printerfor converting color information into patterns.

As described above, image information of a color, which can not berecorded by a receiving apparatus, can be transmitted in a format, whichcan be correctly recognized by the receiving apparatus.

What is claimed is:
 1. An image processing apparatuscomprising:conversion means for converting a predetermined color regionin an input color image into a predetermined image corresponding to thepredetermined color; generation means for generating a character imagerepresenting a name of the color corresponding to the predeterminedimage; and transmitting means for transmitting the predetermined imageconverted by said conversion means, and the character image generated bysaid generation means.
 2. An apparatus according to claim 1, whereinsaid conversion means converts a plurality of colors to predeterminedimages corresponding to the colors, and wherein said generation meansgenerates a list of the predetermined images and names of colors.
 3. Anapparatus according to claim 2, further comprising synthesizing meansfor synthesizing the predetermined images converted by said conversionmeans and the images generated by said generation means.
 4. An apparatusaccording to claim 3, wherein said synthesizing means synthesizes theimage generated by said generation means in a blank portion of thepredetermined images converted by said conversion means beforetransmission by said transmitting means.
 5. An apparatus according toclaim 2, wherein the predetermined images output from said conversionmeans are patterns corresponding to the colors.
 6. An apparatusaccording to claim 2, wherein said transmitting means transmits theimage generated by said generation means in a page different from a pageof the images converted by said conversion means.
 7. An apparatusaccording to claim 1, wherein said transmitting means performs afacsimile transmission.
 8. An apparatus according to claim 1, furthercomprising reading means for reading a color original.
 9. An imageprocessing method comprising the steps of:converting a predeterminedcolor region in an input color image into a predetermined imagecorresponding to the predetermined color; generating a character imagerepresenting a name of the color corresponding to the predeterminedimage; and transmitting the predetermined image converted in saidconverting step, and the character image generated in said generatingstep.
 10. A method according to claim 9, wherein said converting stepconverts a plurality of colors to predetermined images corresponding tothe colors, and wherein said generating step generates a list of thepredetermined image and names of colors.
 11. A method according to claim10, further comprising the step of synthesizing the predetermined imagesconverted in said converting step and the images generated in saidgenerating step.
 12. A method according to claim 11, wherein saidsynthesizing step synthesizes the image generated in said generatingstep in a blank portion of the predetermined images converted in saidconverting step before transmission in said transmitting step.
 13. Amethod according to claim 10, wherein the predetermined images output insaid converting step are patterns corresponding to the colors.
 14. Amethod according to claim 10, wherein said transmitting step transmitsthe image generated in said generating step in a page different from apage of the images converted in said converting step.
 15. A methodaccording to claim 9, wherein said transmitting step performs afacsimile transmission.
 16. A method according to claim 9, furthercomprising a step of reading a color original.
 17. An image processingmethod comprising the steps of:discriminating colors in a color imagecomprising a plurality of pages; converting color regions in the colorimage into predetermined images corresponding to the discriminatedcolors; and generating a list of names of colors which exists in eachpage of the color image and predetermined images corresponding to thelist of names of colors.
 18. A method according to claim 17, furthercomprising the step of transmitting the generated image.
 19. A methodaccording to claim 17, wherein the predetermined image is a patternimage.